1. Field of the Invention
The present invention relates to a structure of an engine cover that covers an upper part of an engine.
2. Background Art
Conventionally, there is a well-known type of engine whose cylinder head is surrounded by devices such as a muffler, a fuel tank and an air cleaner. For example, Japanese Patent Application Publication No. Hei 8-232654 discloses a technique to send cooling air from a fan provided on one side of a cylinder block to the opposite side of the cylinder block, thereby improving cooling efficiency of the engine.
However, according to the above conventional art, sound insulation is not taken into consideration and the engine is provided with only a structure for guiding cooling air wherein the cylinder head and a cylinder are arranged to be surrounded by an air exhaust flange.
On the other hand, attaching of a cover on an engine is an ordinary technique for preventing emission or transmission of vibration, noise, etc. caused by driving an engine. In this case, the cover is arranged to cover an overall body of the engine so that the engine must have a large housing. Furthermore, attachment of the cover must be a time and labor consuming task, thereby making maintenance work harder. Furthermore, for attaching a cover onto a general purpose engine, a different cover is required corresponding to a type of working vehicle to which the engine is mounted.